Propeller.



@in XgcQa-mnq m N @7a/KM@ b Y y B. W. SCOTT.

PROPELLBR.

APPLIU AAAAAAAAAAA Pn. 111111 1.

1,024,032. Patented Apr. 23, 1912.

2 SHEETS-SHEET 1.

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B. W. SCOTT.

PROPELLER.

APPLICATION FILED APB.24, 1911.

1,024,032. Patented Apr. 23, 1912 2 SHEETS-SHEET Z.

@W/www0 l y y B. W 5 C ti) 1%' pfm'w vTo all whom t may concern:

afr-

iar loTelfair?col PROPELLER.

'Be it known t-hat I, BARTON W. Sloo'r'r, a citizen of the United States, residing at .San

' Jose, inthe county of Santa Clara and State of California, have invented certain new and useful Improvements in Propellers; and Il do declare the following to be a full, clear, and exact description of theinvention, Such as will enable others skilledin the art to which it appertains to make and use the same.'

This invention relates to propellers, and

lthe object of the same is to construct, each blade with the largest possible working surface and to so shape its rear edgethat the water delivered therefrom will be thrown straight backjon lines parallel with the axis, rather i than being directedei'ther inward toward or outward away` from suchaxis which would set up currents directed toward the .volume o f water in rear'/ of the propeller that it would haveto Iovercome without a corresponding v resultant forward impulse.

Broadly speaking this object is accomplished by constructing each blade of the propeller with practically two thirds or perhaps three quarters of its body .flat from its front edge or corner backward, and `giving lts rear edge or corner a slight .curl or curve` forward in the direction of rotation, and specificallythe curls or curves of the various blades are struck around lines which converge slowly toward the axis and would reach it (if projected) at a point far in `rear of the propeller. The specific const-ruction is more fully set out in the following specifistructed in accordance with my invention.

Fig.2 is a front end View thereof. Fig.3 is a rear end view. Fig. 4 is a vertical cross section `on the line 4-4 of Fig. l. Fig. 5 is a similar view on the line 5-#5 ofF ig. 1. Fig. 6 is a similar view on the line 6 6 of Fig. l. Fig. 7 isa detail perspective view of one of the blades.

Referring more particularly to the draw.- ings l denotes the shaft and 2 the hub of my improved propeller. On the hub 2 and preferably formed integral therewith is a series of radially project-ing propeller blades 3, three of which are preferably provided.

The contour of each blade as viewed in plan is immaterial to the gistof the present invention, but by preference it is substantially triangular, with one corner united to Speccation of LettersPatent.

Patented Apr. 23, 191m. Application filed' A pn124, 1911. seria1No. 622,883. l

-the hub 2 a second corner 5 standing-somewhat forward ofthe same, and the third corner. t somewhat in rear of the hub and by preference further remote fromthe vaxis than the front corner 5.` As a whole the blade is disposed obliquely to the axis ofthe shaft 1, the degree ofits angle thereto depending upon the purposes. for which the ypropeller is to beused, the speed of its rota-r tion, the weight to be driven, the size, of parts, and other conditions which will not enter into the present'invention.l The major portion ofeach blade (two-thirds or perhaps three-quarters thereof) is substantially 'flat with no orat least Vvery little spiral so that 'what might be called the working surface of each blade bears steadily on the water which it c-leaves andlpresses with kequal force thereon'throughout most of its area. This flat portion of the blade Ihave designated by the numeral 6. But the gist of my idea lies in the fact vthat the outer and rear corner of the `triangular blade are curled'or curved slightly inwardv in the direction of rotation of the propeller,-so that the'wayter which the blade is cleaving will be here tofan extent trapped or cupped by the blade toward the rear edge of its working surface; and I have found by experience-that when the line around which this curve is struck is one that converges slowly toward the axis and will reach it at a point far invrear of the propeller, rather than being one which is parallel with lthe axis vor which diverges there-from to the rear, the result will be that the centrifugal action ofthe water as itleaves vthe propeller is overcome to a great extent or rather is converted into motion in a directionl strictly to the rear and parallel with the shaft l. Obviously, whatever construction of the propeller is adopted which results in forcing water away from it on lines strictly parallel with the direction in which the propeller itself is progressing for ward, the result will .be the greatest eiiciency of such propeller as a'means for driving itself through the water; and with this object in view I may add that the greatest eiiiciency of the structure above -described perhaps lies in the exact degree of curvature and angle of convergence at the points designated by the numerals 7 although consider. ation must be given to the conditions andl other collaterals as suggested above.

From the foregoing description taken in connection with the accompanying drawinvent-ion will be readily understoodl without requiring a more extended explanation.

Various, chan-ges in the form, proportion; and minor details of construction may be re-y sorted to Wit-hout departing from the spirit Ior sacrificing 'any of the advantages of the invention as dened in the appended claim.

l/Vhat is Claimed is:

The herein described propeller having its hub mounted on an axle,r and a series of blades whereof each is substantially triangular in plan with one corner connected to said hub and the other corners disposed :forward and rearward thereof, the Inajor portion of the body of the blade being disposed oblique fnoaaoea to the shaft and substantially flat through out andthe rear corner thereof being curved forward in the direction of rotation around alinewhieh is project-ed would Ineet the prof ter' will be forced away from said propeller on lines strictly parallel with its axis..

' Irl/testimony whereof l have hereunto Set my hand in presence of tWo subseribing'g,- Wit e Y BARTUN W. SCOTT.

lllitnesses: l Y y D. D. TnNNYsoN, B. NICORA. 

